The present invention relates to a new and improved construction of breechblock or breechblock arrangement for an automatic firing weapon with a breechblock carrier or support in which there is rotatably and axially displaceably mounted a substantially cylindrical breechblock body, and further includes a control bolt arranged transversely with respect to the axis of the breechblock body, this control bolt piercingly extending through the breechblock body and with both of its ends engaging in control or cam grooves of the breechblock carrier.
According to a prior art firing weapon of this type the control bolt consists of a sleeve secured to the breechblock body which engages into the control grooves of the breechblock carrier sleeve or breechblock support sleeve and bears against the walls of the grooves. During displacement of the control bolt in the control grooves the same locations of the control bolt always bear against the groove walls, so that flat portions or locations are formed at the control bolt due to plastic deformation or wear.